Space Elevators and Other Alternatives

[Nano-Passion]

So far it seems that space exploration/future tourism/etc has come to a halt due to its expenses.

So what is the status of cheaper alternatives to escaping the gravitational pull from the earth? There was a lot of talk about space elevators but nothing seems to get done (I hope I'm wrong).

 

[russ_watters]

Space elevators are a good idea in theory, but at the moment, no one really knows if they can be built and the expense of the initial construction would make for a long payback in launch cost savings. So no, not much is being done.

 

[mistergrinch]

Well the folks at Project Orion (nuclear fission propulsion) figured out a cheaper way to get out of the gravity well and explore the solar system 50 years ago, but they also calculated that each launch would kill several people on average. Centuries ago this wouldn't have stopped anyone form exploring the oceans. Today we want the universe without risk and without offending anyone, which isn't going to cut it for manned space exploration! We are living in a timid, "can't do", politically correct civilization, and the lack of results compared to previous decades and centuries of exploration speak for themselves...

 

[Nano-Passion]

Space elevators are a good idea in theory, but at the moment, no one really knows if they can be built and the expense of the initial construction would make for a long payback in launch cost savings. So no, not much is being done.

I think its one of those where we need strong leadership to get it started. Thats something that we don't have though, because who is the leader anyways?

Its pretty sad that the world keeps thinking about the now, and postpones the future... Because postponing the future is the easiest thing to do. Why worry about it now when the future can worry about it for us? Phew, that's a big load off our shoulders, its not like we are going to benefit off it anyways in our lifetime.

^^ This is what slows progress, but its society's natural tendency I guess..

 

[russ_watters]

Put off what exactly? Regardless, there are time horizons beyond which it isn't useful to try to plan. If there is no compelling need for the next 50 years or so, there are much more immediate needs to spend our money on.

 

[Nano-Passion]

Put off what exactly? Regardless, there are time horizons beyond which it isn't useful to try to plan. If there is no compelling need for the next 50 years or so, there are much more immediate needs to spend our money on.

Puting off space exploration to be exact.

Yes, urgent needs; but there are also important needs in the long-run. If society simply looks in the short term then we won't be going very far now would be. Just look at politics; they are constantly attending to urgent needs and leaving other problems for the future generations (like our stupendous US debt...)

But perhaps I am quite bias, not everyone is interested in space exploration... but that's likely because they won't be there to witness it.

 

[russ_watters]

Puting off space exploration to be exact.

Yes, urgent needs; but there are also important needs in the long-run. If society simply looks in the short term then we won't be going very far now would be. Just look at politics; they are constantly attending to urgent needs and leaving other problems for the future generations (like our stupendous US debt...)

But perhaps I am quite bias, not everyone is interested in space exploration... but that's likely because they won't be there to witness it.

Bias is only relevant if it prevents you from thinking logically: I'm also a huge fan of manned spaceflight, but that doesn't mean I think it is a practical need. Ie, what long-term need do you see for manned space exploration that outweighs dealing with the US national debt (the two pursuits are essentially mutually exclusive)?

 

[Carrock]

Well the folks at Project Orion (nuclear fission propulsion) figured out a cheaper way to get out of the gravity well and explore the solar system 50 years ago, but they also calculated that each launch would kill several people on average. Centuries ago this wouldn't have stopped anyone form exploring the oceans. Today we want the universe without risk and without offending anyone, which isn't going to cut it for manned space exploration! We are living in a timid, "can't do", politically correct civilization, and the lack of results compared to previous decades and centuries of exploration speak for themselves...

We're willing to let minimally trained people drive cars and frequently kill children and other non drivers which I suppose is brave, "can do" and politically incorrect.
More seriously, Isaac Newton designed the first buildable satellite launcher ( a gun on a mountaintop ) but no one tried to launch a satellite until the available technology made it practical.
With present technology, there are surely far more cost effective ways of spending money on spaceflight.

Bias is only relevant if it prevents you from thinking logically: I'm also a huge fan of manned spaceflight, but that doesn't mean I think it is a practical need. Ie, what long-term need do you see for manned space exploration that outweighs dealing with the US national debt (the two pursuits are essentially mutually exclusive)?

I'd say the two are both (almost) impossible - they involve increased taxes...
People spend money on things like education, entertainment and tourism for which a utilitarian would say they have no long term need.
If enough people wanted the government to spend more money on (manned) space exploration why should it be required to demonstrate long-term need?

In a republic of wolves and squirrels, wolves would eat acorns.

 

[Vanadium 50]

More seriously, Isaac Newton designed the first buildable satellite launcher ( a gun on a mountaintop ) but no one tried to launch a satellite until the available technology made it practical.

That won't work. A gun alone cannot put a satellite into orbit.

 

[JaredJames]

Well the folks at Project Orion (nuclear fission propulsion) figured out a cheaper way to get out of the gravity well and explore the solar system 50 years ago, but they also calculated that each launch would kill several people on average. Centuries ago this wouldn't have stopped anyone form exploring the oceans. Today we want the universe without risk and without offending anyone, which isn't going to cut it for manned space exploration! We are living in a timid, "can't do", politically correct civilization, and the lack of results compared to previous decades and centuries of exploration speak for themselves...

And if you were one of the people told you had to die because they wanted to get to space?

Complete non-sense.

There is a difference between the risk involved once you're in space and exploring to risking the lives of people on Earth simply to get you there.

 

[Andy Resnick]

So far it seems that space exploration/future tourism/etc has come to a halt due to its expenses.

So what is the status of cheaper alternatives to escaping the gravitational pull from the earth? There was a lot of talk about space elevators but nothing seems to get done (I hope I'm wrong).

Your thesis is flawed- on what basis is a space elevator a cheaper technology? It does not exist- you must account for the cost to develop, test, and verify the device before using it.

This is also true of all the other unbuilt "cheaper" alternatives. How much time and money is required to reduce those fanciful ideas into practice?

And, while all that activity is going on, what should happen in the meantime- should existing activities be put on hold? Or are you advocating for NASA's budgets to be doubled/tripled for the next, say, 50 years? And what happens if the magic technology you are advocating does not meet it's promise? What will you say to the taxpayers then?

If you want to be taken seriously, you need to do a better job of accounting for all these expenses/possibilities. Only then can you argue that one method is cheaper than another (already existing and proven) method.

 

[russ_watters]

If enough people wanted the government to spend more money on (manned) space exploration why should it be required to demonstrate long-term need?

Sure, we can do whatever we want, but why would people want to? You implied that space travel was a long-term need. If it's just something we would do for fun, then there is no need for it and you'll have a hard time convincing people to spend trillions of dollars on it when there are things we actually need to spend that money on.

 

[sophiecentaur]

The only reason for any government to decide to put more people, further out into Space would be a military one. That is the only excuse that can be used for such vast expenditure - it was last time and it would be next time. Hopefully we won't be in a post WW2 -type situation for a long long time.
The high tech solution to many problems is often not really the best - just the sexiest. The on-going situation with the stricken Japanese Nuclear Power Stations is a chilling example of just where Technology can take us. Ignoring the potential cost in lives and health, just how much per kWh does this correspond to, in real terms? There will be possible parallel risks in a project such as the elevator but will they be acknowledged? I doubt it.
Meanwhile, we have billions of humans living in really dire circumstances. But that's a different budget; a different compartment in our minds.

 

[ladykrimson]

So far it seems that space exploration/future tourism/etc has come to a halt due to its expenses.

So what is the status of cheaper alternatives to escaping the gravitational pull from the earth? There was a lot of talk about space elevators but nothing seems to get done (I hope I'm wrong).

To actually return to the topic at hand, I believe there are a few problems that need to be resolved before a space elevator can come to be. The space elevator is dependent on a very long cable, one side connected to Earth and one side connected to a station in orbit. This tether would have to be 24,000 miles long. Should it ever snap, a cable that long could do some serious damage on Earth. Radiation exposure for travelers passing through the Van Allen radiation belt is another concern. Also, space debris and micrometeors could damage the tether. Orbital objects that are not in sync and below the maximum altitude of the cable would eventually collide with it. And finally, the materials desired for the tether have not been discovered yet.

 

[Carrock]

That won't work. A gun alone cannot put a satellite into orbit.

As far as I recall, Newton proposed to fire a satellite horizontally into orbit from the top of (the world's highest?) mountain.
If you neglect air friction, it's only necessary to ensure the gun is removed before the satellite comes back round.
If you claim air friction and perturbation means it's not truly in orbit, then the same is true of the ISS.

Sure, we can do whatever we want, but why would people want to? You implied that space travel was a long-term need. If it's just something we would do for fun, then there is no need for it and you'll have a hard time convincing people to spend trillions of dollars on it when there are things we actually need to spend that money on.

My point was that we don't "need" to do most of the things we spend money on and that includes manned space flight.
I doubt much of the money Richard Nixon saved by committing America not to return to the moon before 2000 was spent on things people "needed".

 

[JaredJames]

As far as I recall, Newton proposed to fire a satellite horizontally into orbit from the top of (the world's highest?) mountain.
If you neglect air friction, it's only necessary to ensure the gun is removed before the satellite comes back round.
If you claim air friction and perturbation means it's not truly in orbit, then the same is true of the ISS.

It takes the ISS orbiting at nearly 30,000km/h to remain in an average orbit of 350km. Now take the height of everest (29km) and calculate the speed required to achieve one orbit. (Here's a hint, it's unachievable by a gun).

I doubt much of the money Richard Nixon saved by committing America not to return to the moon before 2000 was spent on things people "needed".

That will need backing up, either way.

 

[russ_watters]

As far as I recall, Newton proposed to fire a satellite horizontally into orbit from the top of (the world's highest?) mountain.
If you neglect air friction, it's only necessary to ensure the gun is removed before the satellite comes back round.

I'm pretty sure that V50 was talking about reality. A 400 year old thought experiment is a useful learning tool, but it doesn't have much to do with reality.

If you claim air friction and perturbation means it's not truly in orbit, then the same is true of the ISS.

Not really. A gun on mount Everest would probably not be able to even get it's projectile back to itself (to complete one orbit) because of that friction and certainly couldn't do two. The ISS can orbit just fine for weeks (months?) without a boost.

...and as said above, that's even assuming it could be built to accelerate a projectile that fast...and not destroy the projectile!

My point was that we don't "need" to do most of the things we spend money on and that includes manned space flight.
I doubt much of the money Richard Nixon saved by committing America not to return to the moon before 2000 was spent on things people "needed".

On the orders of magnitude of cost we're discussing - a trillion dollars or more - the only comparable components of the US budget are things we need to spend money on:
1. Healtcare.
2. Retirement savings.
3. Interest on the debt.
4. The military.

There can certainly be debate about how much and how to spend on these things, but the point is that an exploration trip to Mars, for example, would have a major impact on our ability to spend money on these needs.

 

[sophiecentaur]

If that list is in order of 'preference' or 'urgency' then number 4 could very easily get up to number 1, just like it did in the 50s. Then, if military considerations come into play and another JFK put up the challenge, all your spending money dollars could go, literally, up the shute! Though, as a weapon, perhaps such a big target would be a bit vulnerable. SO perhaps not.

 

[Carrock]

I'm pretty sure that DH was talking about reality. A 400 year old thought experiment is a useful learning tool, but it doesn't have much to do with reality. Not really. A gun on mount Everest would probably not be able to even get it's projectile back to itself (to complete one orbit) because of that friction and certainly couldn't do two. The ISS can orbit just fine for weeks (months?) without a boost.

...and as said above, that's even assuming it could be built to accelerate a projectile that fast...and not destroy the projectile! On the orders of magnitude of cost we're discussing - a trillion dollars or more - the only comparable components of the US budget are things we need to spend money on:
1. Healtcare.
2. Retirement savings.
3. Interest on the debt.
4. The military.

There can certainly be debate about how much and how to spend on these things, but the point is that an exploration trip to Mars, for example, would have a major impact on our ability to spend money on these needs.

It takes the ISS orbiting at nearly 30,000km/h to remain in an average orbit of 350km. Now take the height of everest (29km) and calculate the speed required to achieve one orbit. (Here's a hint, it's unachievable by a gun).


That will need backing up, either way.

There is plenty of evidence a space gun is feasible but not necessarily economic. eg
http://www.astronautix.com/lvs/maret2g1.htm" .
There are certainly economic limits to the velocity a gun can impart, but I'd be very surprised if you can find any theoretical limit.

If you claim air friction and perturbation means it's not truly in orbit, then the same is true of the ISS.

A gun on mount Everest would probably not be able to even get it's projectile back to itself (to complete one orbit) because of that friction and certainly couldn't do two. The ISS can orbit just fine for weeks (months?) without a boost.

I agree 100% with this.
Please specify for how long an object has to be traveling at orbital velocity before it is in orbit.

I doubt much of the money Richard Nixon saved by committing America not to return to the moon before 2000 was spent on things people "needed".

That will need backing up, either way.

I think it would be impossible to get ten people to agree on whether any particular use of the money was needed.
I failed to state that my real objection to saying whether something is 'needed' or not is that it is usually an attempt to put an objective veneer on a subjective value judgment.

Back on topic...
Manned spaceflight: only justifiable to transport people to moons and planets where they are better than machines - whether they are more cost effective is arguable.

Space Elevator: currently too expensive and probably always too dangerous.

Mars voyage: worth doing eventually, but not before returning to the moon. (There was a plan in the Apollo program to build a space gun (ok, linear accelerator) to launch spacecraft from the moon.) - oops, off topic again...

 

[JaredJames]

There is plenty of evidence a space gun is feasible but not necessarily economic. eg
http://www.astronautix.com/lvs/maret2g1.htm" .
There are certainly economic limits to the velocity a gun can impart, but I'd be very surprised if you can find any theoretical limit.

I agree 100% with this.
Please specify for how long an object has to be traveling at orbital velocity before it is in orbit.

Did you check the numbers for a speed that you'd have to fire a projectile horizontally off everest for it to orbit only once?

Not to mention the fact we don't have materials that can survive those sort of speeds (within an atmosphere). For proof, see the problems we have with scram jets - the air resistance destroys them.

 

[Vanadium 50]

If you launch with a gun from earth, the lowest point is exactly where you launched it from - i.e. on the ground. You can't get it in a real orbit (where the lowest point is > 100 km up)

 

[mistergrinch]

On the topic of space guns, I like this design for a nuclear space cannon: http://nextbigfuture.com/2009/02/nuclear-orion-home-run-shot-all-fallout.html

 

[D H]

I'm in a bed & breakfast with a lousy internet connection, so I can't see than nextbigfuture.com reference. I have my suspicions, however. Is it all blown out of proportion? (Sorry for the bad pun.) Does it whitewash / completely ignore known downsides? Does it whitewash / completely ignore the fact that such a device hasn't been built, even on a vastly reduced scale? nextbigfuture.com is not a reputable source.

This gets to the heart of all of these next big futures in aerospace engineering. None of them are aerospace engineering. Certainly not space elevators. They're still science fiction. Rail guns? Science fiction. Fission-based rockets? Science fiction.

In this case, given what just happened in Japan, it is science fiction that ignores political reality. Nuclear rockets are a nonstarter just because of the public perception that anything nucular is bad, and not just pollute the local stream bad. Godzilla / Armageddon bad.

 

[russ_watters]

If that list is in order of 'preference'...

The list is in the order they popped into my head. But I think they are the largest individual expenditures of the US government.

 

[russ_watters]

There is plenty of evidence a space gun is feasible but not necessarily economic. eg
http://www.astronautix.com/lvs/maret2g1.htm" .

No, there really isn't. That link, for example, is a rocket fired from a gun, not a gun alone.

Since it's never been done, it is certainly a stretch to say it is feasible, in any sense of the word.

There are certainly economic limits to the velocity a gun can impart, but I'd be very surprised if you can find any theoretical limit.

Besides the fact (again) that a gun alone can't put an object in orbit (the payload needs to contain a rocket in order to shape the trajectory into an orbit), the theoretical limits that haven't been dealt with yet would include g-forces on materials, frictional heating (both in the gun and out of the gun) and gas dynamics.

I agree 100% with this.
Please specify for how long an object has to be traveling at orbital velocity before it is in orbit.

I wouldn't consider an object to be in orbit unless it's trajectory carried it around the Earth at least once without crashing. Otherwise you could throw a baseball and consider it to be in orbit. While it may be instructive to do that in some contexts, quibbling about it in this thread seems like trolling to me. No matter what label you put on it, you obviously do see the vast difference between what the ISS is doing and what a gun on Everest could do.

I think it would be impossible to get ten people to agree on whether any particular use of the money was needed.
I failed to state that my real objection to saying whether something is 'needed' or not is that it is usually an attempt to put an objective veneer on a subjective value judgment.

You can't get more than about 6 of 10 to agree on even the most fundamental scientific ideas, but the universe doesn't care if people understand it or not, so that requirement isn't really worth much.

If tomorrow, the people of the US decided that all government healthcare expenditures be re-directed to a crash-program to put a man on Mars, it wouldn't change the reality of the fact that healthcare spending is needed. One way or another, people will spend money on healthcare.

However, the point of needs vs wants is still relevant enough: because those needs I listed are very real and very, very important, you'll have a very, very hard time convincing a large enough to matter fraction of the population that spending money on the 'want' of a mission to Mars is more important.

Manned spaceflight: only justifiable to transport people to moons and planets where they are better than machines - whether they are more cost effective is arguable.

In a world of fininte money, "cost effective" is a component of "better". It's part of the reason the space program is structured the way it is.

 

[russ_watters]

I'm in a bed & breakfast with a lousy internet connection, so I can't see than nextbigfuture.com reference. I have my suspicions, however. Is it all blown out of proportion?

Er, well, it's not what you were thinking: it's a Project Orion knockoff. I suppose if you really reach, you could call a nuclear bomb-powered rocket a gun, since it propels itself with explosions like a glossed-over gun (which doesn't propel its projectile with explosions, despite the popular perception)...

 

[D H]

Er, well, it's not what you were thinking: it's a Project Orion knockoff.

That's exactly what I was thinking. Project Orion was science fiction, is still science fiction, will remain science fiction for a long, long time. The true next big future has to be technically, economically, and politically feasible. Orion might be technically feasible, so it gets one out of three, maybe.

 

[ngc1333]

And if you were one of the people told you had to die because they wanted to get to space?

Complete non-sense.

There is a difference between the risk involved once you're in space and exploring to risking the lives of people on Earth simply to get you there.

Air pollution kills millions of people every year, just to put things in prospective.

 

[JaredJames]

Air pollution kills millions of people every year, just to put things in prospective.

Your point being?

 

[sophiecentaur]

Air pollution kills millions of people every year, just to put things in prospective.

I sort of see where you're coming from but two wrongs don't make a right.
The number of deaths caused by some sources of pollution has been reduced greatly, by legislation. Pity the legislation seldom seems to reach as far as the poor and underprivileged masses throughout the world. But that's commercial pressures - which, btw, are unlikely to overcome the objections of rich and articulate societies which may perceive the risk of an elevator failure as far outweighing the risks to gold miners in South America.

 

[clope023]

Sure, we can do whatever we want, but why would people want to? You implied that space travel was a long-term need. If it's just something we would do for fun, then there is no need for it and you'll have a hard time convincing people to spend trillions of dollars on it when there are things we actually need to spend that money on.

Sagan called this idea your perpetrating a fallacy of the excluded middle

 

[sophiecentaur]

I looked at the movie. Sagan disappointed me a bit, with his attitude. He implies that young people would have "something to aspire to" in the shape of space exploration. The actual exploration or colonisation would be open to a tiny part of the Earth's population (condemning the majority to vicarious appreciation only) the majority and the entertainment value of the activity would be no more than what's available from Football on TV on a Saturday afternoon (which is far more of a feasible aspiration for your average young lad and far less in £ per head).

Science is a vast field with many potential contributions to the future of Humankind. Space travel is not the only sexy thing to investigate and the cost/benefits are questionable. How come people seem to be determined to treat Space Exploration as the equivalent to the Wild Frontier? The ideas get fuzzier and fuzzier when they are challenged with the actual timescale involved. There's nowhere out there which is near enough to take surplus millions of population. I'm sure people have the Azimov trilogy in their minds when they talk of a 'future in Space'. Or is it 'warp drive' that will solve the problems? Without ftl, we are pretty well stuck in the Solar System.

Space, as a source of materials, is attractive but can you really imagine the quality of life of a long-term colonist on Mars? Sounds like more exploitation followed by eventual demands for Independence , followed by revolution.

The space elevator is a fantastic thought exercise but could we get the food situation sorted first, please?

 

[Carrock]

There is plenty of evidence a space gun is feasible but not necessarily economic. eg
http://www.astronautix.com/lvs/maret2g1.htm"

No, there really isn't. That link, for example, is a rocket fired from a gun, not a gun alone.

Since it's never been done, it is certainly a stretch to say it is feasible, in any sense of the word.

Many scientists believe that a large satellite was succesfully launched from Earth some time ago using inter alia processes that could be used in a space gun. (see below)
So if something is feasible once it's been done then such a satellite launcher is feasible.

Besides the fact (again) that a gun alone can't put an object in orbit (the payload needs to contain a rocket in order to shape the trajectory into an orbit), the theoretical limits that haven't been dealt with yet would include g-forces on materials, frictional heating (both in the gun and out of the gun) and gas dynamics. I wouldn't consider an object to be in orbit unless it's trajectory carried it around the Earth at least once without crashing. Otherwise you could throw a baseball and consider it to be in orbit. While it may be instructive to do that in some contexts, quibbling about it in this thread seems like trolling to me. No matter what label you put on it, you obviously do see the vast difference between what the ISS is doing and what a gun on Everest could do.

I had thought that saying "neglect air friction" would be enough to indicate I didn't think one spacegun could launch a satellite to above launch height; if there is no additional source of kinetic energy you need two.


Part of the tried and tested mechanism of launching a large satellite:
Hit the Earth with a very large object.
This will cause large parts of the Earth ( and the impactor) to be ejected upwards from many places at various angles and velocities (much like meteors are believed to have expelled Martian material).
A typical mechanism for getting some of this material into orbit:
Some material traveling horizontally(say) at 'sufficient height' is hit by more energetic material from another launch site traveling forwards and upwards; both projectiles are fragmented in an inelastic impact; some of the debris ends up traveling in a closed orbit which prevents it hitting the Earth indefinitely.
(Because of the large scale, friction between clouds of gas and debris was more significant.)
The debris then self assembled into a satellite.
The satellite is currently being boosted into a higher orbit but is still the second brightest object in the sky.
I agree there is a vast difference between what the ISS is doing and what that satellite launcher did.

Wile hitting the Earth very hard in one or two places to launch a satellite is neither safe nor economic nor desirable, if you think it an unfeasible way to create a one use only gun I believe you will be in a minority.

In a world of fininte money, "cost effective" is a component of "better". It's part of the reason the space program is structured the way it is.

Is it really "better" to have people in the ISS proving it's still possible to live in space rather than back on the ground or actually going somewhere?

Incidentally, is it really trolling when people repeatedly disagree over how to misuse the word 'orbit'?

 

[JaredJames]

Many scientists believe that a large satellite was succesfully launched from Earth some time ago using inter alia processes that could be used in a space gun. (see below)
So if something is feasible once it's been done then such a satellite launcher is feasible.

Do they believe it or is it fact?

I had thought that saying "neglect air friction" would be enough to indicate I didn't think one spacegun could launch a satellite to above launch height; if there is no additional source of kinetic energy you need two.

Two guns? So you'd fire the projectile and then catch it in another to shoot again?

Part of the tried and tested mechanism of launching a large satellite:
Hit the Earth with a very large object.
This will cause large parts of the Earth ( and the impactor) to be ejected upwards from many places at various angles and velocities (much like meteors are believed to have expelled Martian material).

Tried and tested? We've never tried nor tested this method. It takes a major impact to do this.

A typical mechanism for getting some of this material into orbit:
Some material traveling horizontally(say) at 'sufficient height' is hit by more energetic material from another launch site traveling forwards and upwards; both projectiles are fragmented in an inelastic impact; some of the debris ends up traveling in a closed orbit which prevents it hitting the Earth indefinitely.
(Because of the large scale, friction between clouds of gas and debris was more significant.)
The debris then self assembled into a satellite.
The satellite is currently being boosted into a higher orbit but is still the second brightest object in the sky.
I agree there is a vast difference between what the ISS is doing and what that satellite launcher did.

What is this non-sense? Sounds like a poor way of describing a potential origin of the moon.

Wile hitting the Earth very hard in one or two places to launch a satellite is neither safe nor economic nor desirable, if you think it an unfeasible way to create a one use only gun I believe you will be in a minority.

Sources please. Show us how it is feasible (check the definition of that word before you reply).

Is it really "better" to have people in the ISS proving it's still possible to live in space rather than back on the ground or actually going somewhere?

The ISS is not even close to space travel. They are not comparable.

Incidentally, is it really trolling when people repeatedly disagree over how to misuse the word 'orbit'?

It is if you are nit picking just to perpetuate the argument.

 

[mistergrinch]

Sophie, you should read "Mining the Sky" by John Lewis and "The High Frontier" by Gerard O'Niell if you don't think there's much potential in the near future for space colonization. Lewis estimates that the solar system could support 10^16 humans! The asteroids are a fantastic opportunity; one small asteroid may have precious metals worth trillions of dollars, and the elements needed to support life are all out there in abundance. A hollow asteroid for example would be a *much* safer and more stable place for humans to live than this planet, because there wouldn't be any tsunamis, climate change, super-volcanoes, etc. and they would be out Earth's gravity well so space travel would be very cheap.

 

[JaredJames]

A hollow asteroid for example would be a *much* safer and more stable place for humans to live than this planet, because there wouldn't be any tsunamis, climate change, super-volcanoes, etc. and they would be out Earth's gravity well so space travel would be very cheap.

Are you just ignoring all the problems that go with such an idea?

Let's just start with radiation - we have a lovely atmosphere to deal with the majority of it, what does an asteroid have?

 

[mistergrinch]

A hollow asteroid has thick rock walls to block cosmic rays and solar storms, obviously...

 

[JaredJames]

A hollow asteroid has thick rock walls to block cosmic rays and solar storms, obviously...

How sweet, you make it sound so simple.

 

[mistergrinch]

Simple? Definitely not, but clearly possible once our space industry has reached the asteroids. In general, colonizing space will be the hardest thing human beings have ever attempted, but it's also the most necessary thing if we want to have any kind of long-term future, wouldn't you agree?

 

[JaredJames]

Simple? Definitely not, but clearly possible once our space industry has reached the asteroids. In general, colonizing space will be the hardest thing human beings have ever attempted, but it's also the most necessary thing if we want to have any kind of long-term future, wouldn't you agree?

It's going to be a lot easier to get our food / population under control than to colonise space.

Once we've got those two out of the way, we're good for a few billion years. Long enough for you?

 

[mistergrinch]

We will never get things under control on this planet. There is no reason why we have to accept random catastrophes like tsunamis and super-volcanoes killing millions of people, other than a lack of imagination and ambition!

 

[JaredJames]

You do realize that no other place in the solar system is as hospitable as Earth?

You're only plagued by those things if you live in areas prone to them - when was the last time London was destroyed by a natural disaster?

Obviously, we can't stop them, neither can we relocate everyone. We can work to limit damage and it's a hell of a lot easier to solve our problems here than simply overflow into space - where the problems will continue.

 

[mistergrinch]

Sorry but I don't see what is inhospitable about a suitably designed space habitat like a rotating hollow asteroid. A network of such worlds with an independent industrial base should be able to maintain its technology and population long after Earth civilization has returned to a post-industrial Stone Age or been wiped out by some catastrophe!

 

[Nano-Passion]

Its interesting, across space exploration arguments I usually see two sides. Enthusiasts vs. pessimists of the idea.

I stand somewhere in the middle, though the idea of space exploration/colonization is very exciting to say the least.

 

[JaredJames]

Its interesting, across space exploration arguments I usually see two sides. Enthusiasts vs. pessimists of the idea.

I stand somewhere in the middle, though the idea of space exploration/colonization is very exciting to say the least.

I love the idea of space travel and exploration.

But, I also see the more pressing needs of the planet.

It's a balancing game and on these scales, space travel just doesn't weigh up.

 

[Vanadium 50]

when was the last time London was destroyed by a natural disaster?

Um...1666?

Seriously, while not London, people often forget Lisbon was destroyed by an earthquake in 1755.

 

[sophiecentaur]

What makes me smile is the assurance of the pro-spacers that humans will, somehow, change their basic nature and create ideal environments by starting from scratch on assorted asteroids and small planets. The only reason that we haven't died out already is surely because the Earth is (even now) still capable of absorbing the worst of our irresponsible behaviour.

It may well be possible to battery-rear humans in artificial worlds but to what end? This figure of 10^16 humans all 'living' in the solar system is just so grotesque. What would be the point? Who would benefit from it? How would that solve the situation on an over-crowded Earth? However you do the sums, the cost in energy of getting a person from Earth to somewhere else in the Solar System would be more than they would consume, in other ways, in a lifetime down here. How could one suggest we ship them all off to Mars (equivalent to Australia and the new world as in the past)?

Humane (with an 'e') population regulation is the only solution to a happy future for our life on Earth. It's only the wealthy few who promote such extravagant expense as Space Tourism. Unmanned investigations are such good value for finding out about our universe compared with Buck Rogers type zapping around the Cosmos. Perhaps, when we can honestly say that everyone 'down here' is catered for adequately, there may be a time for a large off-Earth presence.

btw, I am heartened by the number of other contributors on this forum who share my skepticism about all this stuff. A very mature population; not just boy racers.

 

[sophiecentaur]

Um...1666?

Seriously, while not London, people often forget Lisbon was destroyed by an earthquake in 1755.

The 'great fire' was man made and could just as easily be caused in a space station. The difference with Earth bound disasters is the inherent healing process in the natural system of which we are a part. Just leaving Earth wouldn't solve the problem of disasters.

 

[JaredJames]

Um...1666?

My point exactly (although I'm not entirely sure I'd go with it being a natural disaster, a tad too man made for my liking ).

Seriously, while not London, people often forget Lisbon was destroyed by an earthquake in 1755.

Wow, as close as 1755

My point is that there are places on the planet that are relatively 'inactive' so far as these things go and other places that are built right on top of the fault lines.

I agree that there are natural disasters that could affect these areas, but they are 1 in a 10,000 year (or what ever the rather large number is) events that we really don't consider or have need to.

I subscribe very much to the thought of "you build on a volcano/fault line etc, you accept the risk". Poor or otherwise, we know the dangers and it is constant pro vs con.

Anyhow, back to my point, mistergrinch is making far too big a deal out of natural disasters so far as the planet goes. As sophie says, Earth is very good at absorbing the crap we through at it and frankly, I'm not surprised it "lets off some steam" every now and then and don't see how anywhere else in the solar system offers us a safer / more hospitable environment.

 

[bonker]

The thing that gets me with the space elevator is the basic physics. How is angular momentum conserved? The glib response is usually that the Earth is slowed as the payload rises to conserve angular momentum. But this does not address the possibility of the orbiting station being slowed and essentially dragged back to earth, also conserving angular momentum. You'll need to keep sending fuel to keep the station moving to counter this, yes?